New paper from the Schwab lab.
The secret of the major birch pollen allergen Bet v 1 – identification of the physiological ligand.
Christian Seutter von Loetzen, Thomas Hoffmann, Maximilian J. Hartl, Kristian Schweimer, Wilfried Schwab, Paul Rösch and Olivia Hartl-Spiegelhauer (2013)
The major birch pollen allergen Bet v 1 is the main elicitor of airborne type I allergies and belongs to the family 10 of pathogenesis related proteins. Bet v 1 is the most extensively studied allergen, and is well characterized on the biochemical and immunological level. However, its physiological function remained elusive. Here we present the identification of quercetin-3-O-sophoroside (Q3OS) as the natural ligand of Bet v 1. We isolated Q3OS bound to Bet v 1 from mature birch pollen and confirmed its binding by reconstitution of the Bet v 1:Q3OS complex. Fluorescence, UV/VIS as well as HSQC titration experiments and the comparison with model compounds, such as quercetin, indicated the specificity of Q3OS binding. Elucidation of the binding site by NMR combined with a computational model resulted in a more detailed understanding and shed light on the physiological function of Bet v 1. We postulate that the binding of Q3OS to Bet v 1 plays an important but as yet unclear role during the inflammation response and Bet v 1 recognition by IgE.
